These recordings were made
with a high resolution, studio quality, digital recording system, then
converted to LAME 128kbps encoded MP3s. We've listened long and hard
to ensure there is no audible degradation from the original WAV files
to these MP3s. They represent a quick snapshot of what we heard during
the review. Two recordings of each noise level were made, one from a
distance of one meter, and another from one foot
away.

The one meter recording
is intended to give you an idea of how the subject of this review sound
in actual use  one meter is a reasonable typical distance between
a computer or computer component and your ear. The recording contains
stretches of ambient noise that you can use to judge the relative loudness
of the subject. For best results, set your volume control so that the
ambient noise is just barely audible. Be aware that very quiet subjects
may not be audible  if we couldn't hear it from one meter, chances
are we couldn't record it either!

The one foot recording is
designed to bring out the fine details of the noise. Use this recording
with caution! Although more detailed, it may not represent how the subject
sounds in actual use. It is best to listen to this recording after you
have listened to the one meter recording.

For a high end, blazing performance, dual-graphics, overclocked monster of
a system, we know of no quieter power supply than the Energy Plus. Acoustically,
the Energy Plus has surpassed our expectations of what is possible from a quiet
power supply and set a new standard. With a fan that doesn't begin to increase
in speed until 250W output, it will take a concerted effort to force
the Energy Plus to become noisy  a nice change from the need to put effort
into preventing added noise.

One question that we have is whether the quieter performance has come at the
expense of cooling and reliability. That's not to say that the Energy Plus is
undercooled, but it doesn't quite measure up to the excellent thermal performance
that we saw in their original S12's. That said, the high 550W and 650W capacity
points mean that they should operate well below 50% load most of the time. With
that much headroom, it's hard to imagine the cooling system being inadequate.

As expected for an 80 Plus power supply, efficiency was top notch, and the
85% peak very close to the highest we've measured. That said, the high efficiency
does need to be put into perspective. A little extra efficiency is nice to have
in a powerful system, but an extra two or three percentage points doesn't work
out to much of an energy saving unless the load is ridiculously high 
which kind of defeats the purpose. In the range that most people will use it,
the Energy Plus models are not any more efficient than Seasonic's existing models.

The biggest strike against the Energy Plus is its price. US$150 for a power
supply is far from pocket change, and there are plenty of cheaper alternatives
that are just as quiet at lower levels. To reiterate: The Energy Plus is a power
supply for connoisseurs: It's engineered beyond what most people need, but if
you're looking for a special power supply for that special system, the Energy
Plus fits the bill perfectly.

Nice as it is, we can't help asking where are the lower capacity models that
perform like the OEM models that we've already seen from Seasonic. We know they
are capable of building a power supply that is 84% efficient at 65W. Where is
the 330W Energy Plus that can match the SS-300SFD for low-load efficiency? Here's
to hoping Seasonic brings one out for energy conscious silent PC enthusiasts.